Internal mandrel



Nov. 9, 1948. H. c. MYERS INTERNAL MAN REL Filed April 27, L945 IllATTORNEY.

l atented Nov. 9, 1948 Harold Myers, Kans Butler Manufacturin as City,Mo., assignor to g Company, Kansas City,

' Mona corporation of Missouri i 1. Application April 27, 1945, SerialNo. 590,626

This invention relates toimprovements in internal mandrels used inbending pipe and tubing.

and refers more particularly to mandrels having a flexible strandedmemberconnecting the rolling members to themandrel body.

Heretofore internal mandrels have employed link chains flexible 01117.111. one plane for connecting the rolling members or balls to themandrel body. The use of such mandrelsrequires accurate adjustment orpositioning of the mandrel with respect to its linkage-so the bendingplane of the mandrel coincides with the plane on which the pipe is to bebent. The time required for making the above adjustment results in anoperational slow-down. i

An important object of this invention is to provide an internal mandrelhaving a flexible stranded member connecting the rolling members to themandrel body.

.Another objectis to'provide an internal man- I drelhaving a simple andrugged construction,

A'further object is to provide an internal mandrel having rollingmembersadjustably mounted on the flexible stranded member. j Other andfurther objects of this invention will appear from the followingdescription.

Inthe accompanyingdrawings which form a part of the instantspecification and are to be read in conjunction therewith and in whichlike reference numerals are usedto indicate like parts 30 in the variousviews, I

Fig. 1 is a diagrammatic top plan view showing a hydraulic bendingmachine equipped with an internal mandrel,

Fig. 2 is an enlarged sectional View of an in-. 35

ternal mandrel embodying the invention positioned in apipe preparatoryto bending,

Fig. 3 is. a view of the nandrel and .pipe shown in Fig. 2 after thepipe is bent showing the position assumed by'the rolling members duringthe 4 bending of the pipe, I I

Fig. 4 is a view taken on the line 4-4 in Fig. 2, and

Fig. is a view taken along the line 55 in Fig. 2 in the direction of thearrows.

Referring to Fig. 1 a hydraulic bending machine is diagrammaticallyshown which may be used in conjunction with an internal mandrelembodying the present invention. The numeral I0 designates the table ofthe bending machine with clamping arm I I and swinging arm l2 adjacentone end thereof. The arms I I and I2 are equipped respectively with abearing block I 3 and a clamping die I4 which cooperate with a bendingform I5 to hold the tubing during the bending 55- completion of. abending operation in whicha 2 Claims. (01. 3)

operation. Above the bearing block l3 and between the bearing block andhead l3a are rollers l3b which permit longitudinal movement of thebearing block along the pipe or tubing during he bending operation. Thebearing block assembly and clamping die. I 4 are adjusted by the screwassemblies .Ila and 12a in each of the arms. Swinging arm I2 and bendingform I5 pivot .or rotate together. Swinging larm I2 is shown in dottedlines in a position occupied by it at the quarter bend is made in apipe. This portion of the bending machine, in so far as its operation isconcernedis essentially similar to that shown 3 in the patent to J. 0.Wilson No. 1,007,834. Mandrel rod I6 extends longitudinally of table I0and has a mandrel body I l aflixed at one end adjacent clamping. die I3.At its other end rod I6 issup ported on a frame I8 at theend of thetable and is. actuated by a hydraulic cylinder I9 capable of imparting areciprocating movement to rod Itito move the mandrel into an operativeposition andto withdraw. the mandrel from the bend of the pipe .onthecompletion of the bendingopera tion. Beneath table I0 is a hydraulicactuating mechanism for rotating the'swinging arm and bending formcomprising a hydraulic cylinder 20,

. roller-chain 2|, guide. sprocket 22, and drive sprocket 23. Thismechanism is conventional and is very diagrammatically shown in dottedlinesin the drawings in. the interest of simplifying the disclosure. j iH Having described a type of bending machine in which the mandrel ofthis invention may be used, the mandrel is now referred toand is bestillustrated in Figs. 2 and 3. The mandrel comprises a tubular mandrelbody ll screw threadedlyconnected to rod IS. A double stranded flexiblewire rope 24 has its free ends slidably anchored within body IT. This'isaccomplished by an anchoring nut assembly 25 securely fastened tothefree ends of the rope and confined withinthe body by a flange Ila.Adjacent the bended end of rope 24 is a sleeve like plug 26 which hastwo axial apertures 26a through which the two parts of rope arethreaded. A cross pin or stop 21 positioned through the loop of the ropefits into a groove 26?) in. the end of the plug, as shown in Fig. 5, andprevents a cutting or crimping of the wire rope.

. In addition stop 2 spreads the loop of rope wedging its parts againstthe plug frictionally anchoring the rope in the plug. I It is to benoted that the outside diameter of plug 26 is sufliciently small topermit it to pass through the flanged aperture plug 21 'plished.

The mandrel is easily assembled. First the end portions of strandedmember 24 are threaded through the apertures in plug 26 and stop 21 isinserted in the loop of the stranded member. The plug is then forcedagainst the stop to securely anchor it at the doubled end thereof. Theenchoring nut assembly 25 is securely fastened to the free ends of thestranded member and this assembly is inserted in the threaded end of themandrel body and slipped into the position shown in Fig. 2. Arbor member28 is then slipped over the plug and arbor member 29 is threaded on andadjusted longitudinally thereon.

The operation of the assembled mandrel in conjunction with the bendingmachine is obvious from what has gone before.

The assembled mandrel is screwed on mandrel rod I6 of the bendingmachine. A pipe or tubing 30, which is to be bent, is slipped over themandrel, as shown in Fig. 2, and the clamping die l3 and pressure die [4are adjusted against the pipe or tubing. Then an actuating lever, notshown in the drawings, is pressed to operate hydraulic actuator l9 whichadvances mandrel l1 into an operative position relative to bending formand the swinging arm. The hydraulic mechanism by which the pipe is bentis next actuated to rotate arm i2 and bending form 15 from their fullline position to their dotted line position, shown in Fig. 1. This formsa quarter bend in pipe 30, as shown in Fig. 3. The angle ,of bend may beselectively adjusted to any desired degree. During the bending operationarbor mem bers 28 and 29 assume the position within the bend of pipe 30,as shown in Fig. 3, internally supporting the tube wall thus maintainingthe tube diameter throughout the bend. When the bend is completeactuator I9 withdraws mandrel rod l6 extracting arbor members 28 and 29from the pipe bend. Dies l3 and 14 are then released provided aninternal mandrel which is universally flexible as distinguished from theaxis of conventional type of mandrel which is movable only in one plane.The arrangement is such that the device is rugged, of simpleconstruction and easily assembled. The construction provides an internalmandrel that is usable in conjunction withmany types of bending machinesand one that does not require careful alignment of the mandrel with theplane in which the pipe is to be bent.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the invention.

.It will be understood'that certain features and subcombinations are oi-utility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. In an internal mandrel for use in bending pipe and tubing, a tubularbody, arbor members, a flexible connection between the arbor members andbody including a doubled stranded member having its free ends anchoredwithin the tubular body, an apertured plug secured on said strandedmember and one of said arbor members adjustably mounted on said plug. ii

2; In an internal mandrel for use in bending pipe and tubing, a tubularbody, arbor members, a flexible connection between the arbor members andbody including a doubled stranded member having its free ends anchoredwithin the tubular from engagement with pipe 30 and the pipe is removedfrom the machine. Arm l2 and bending form 15 are then rotated in areversedirection to their original position shown in full lines in thedrawings.

While rope 24 is illustrated as a wire rope it is contemplated that anysuitable stranded material may be used. The stranded characteristic ofmember 24 contributes an inherent universal flexibility to theconnection. In other words the doubled rope or flexible portion ;of themandrel is free to bend in any plane radial to its axis.

It will be seen that the objects of this invention have beenaccomplishech There has been body, an apertured plug strung on saidstranded member, a stop inserted in the loop of the stranded member andengaging the end of the plug, and one of said arbor members adjustablymounted on said plug.

v HAROLD C. MYERS.

REFERENCES CITED 1 The following references are of record in the file ofthis patent;

UNITED STATES PATENT Number Name Date 174,609 Wright Mar. 7, 18761,007,834 Wilson Nov.-7, 19-11" 1,016,770 Persons Feb. 6, 1912 1,856,597Stjarnstrom May 3, 1932 FOREIGN PATENTS Number Country Date I I 532,068France Nov. 7, 1921

